Some of these roofs make excellent astronomy binoculars. The Celestron Regals, especially the 8xRegal, the Nikon Monarch 10x42 and the Bushnell Legend 8x42, are all good choices. As a bonus, these choices equip the user with a nice lightweight piece that can be used for terrestrial use.

I have an 8x42 roof that is a sibling of the Celestron Regal mentioned in EdZ's report. I quite enjoy them for every kind of use even for astronomy. They make a perfect take-along pair for trips. No hesitation at all in recommending these.

I have an 8x42 roof that is a sibling of the Celestron Regal mentioned in EdZ's report. I quite enjoy them for every kind of use even for astronomy. They make a perfect take-along pair for trips. No hesitation at all in recommending these.

Hi Ed,

Thanks!

Hope you can check out the Vortex Razor or the Vortex Viper one day. They are expensive, but everyone who uses those before raves about them. I just wonder how they compare with the Nikon Monarch or the Bushnell legends or better still the Fujinon.

The disadvantage is mainly the price. Once you've taken that hurdle, you will find the best roofs to be stunning astro-instruments. I have had both roofs and porros in the best quality available. Performance wise, they are both great. The roofs are generally more compact. For a given price, porro's can't be beat for sheer image quality. Once you go to the bigger sizes, say 70mm and up, porros are your only option.

as stated here many times, all binoculars are compromisesthe various compromises make one better than another for "whatever"my 6.5x21 pentax papillios will work for astronomy- somewhatmy 25x150s will work for birding-if the birds come to me

After obtaining a pair of 10x42 Steiner's quite by chance, I was hooked on the quality feel, great views, compact size and light weight. A giant step above my Pentax PCF and Nikon AE porro 50's. I mean really, side by side comparisons were dramatic (however, better quality porros can be equallly as stunning)! I began a search for a great lower power pair and after MUCH research decided on the 8x42 Vanguard Endeavor ED's. The value is hard to ignore. Now I have a couple pair of world class glass for bargain prices.

For astronomy you need well designed and executed Porro binoculars. Well designed and executed roofs will be just as effective. The problem is that roofs, everything else being equal, are more expensive to manufacture. They are indeed more compact but this becomes a limitation when the aperture is more than about 63mm, as roofs do not displace the optical path sideways, so they cannot adjust to IPD smaller than their objective size). You will never see a 16x70 roofs version of a Fujinon 16x70. Therefore roofs will never completely replace Porro binoculars for astronomy.My two cents, and worth every penny Marco

Out of 30 odd binos [third of them are roof's] my most used hand held astro. bino is a roof, my Minox 10x58 ED BD. Behind this would be my Leica 12x50 BN. These are not however inexpensive binoculars. Both give just excellent images. As others have said you do have to go for a quality roof, the more entry version can give spiking and a less then pin point image. However, with the rise of good quality affordable Chinese ED's this is now less of a concern.

The prisms in a roof prism binocular have to be precisely aligned for them to perform well and from what I have seen you have to pay a lot for that. At least 4 or 5 times more than a porro binocular to get the same result. But your reward is a much smaller lighter binocular.

As Rydberg stated, it costs more to make roof prism designs equal to porro prism performance. People pay the extra money for the compact size under ~50mm. Roof prism isn't more expensive because it's better optically. A fact few seem to recognize.

That said, high-end roof prism designs are better than low-end porro prism models simply due to the care in manufacturing. But at the end of the day, i.e. when the sun sets, you get far more for your money in porro designs.

Any binocular benefits from a sturdy mount. The last thing I care about is binocular weight. I'm going to mount it to a tripod if it's worth looking through and I have the time/circumstance. Even hand-held, heavier binoculars are better because they don't jump every time your heart beats. Not so much to carry around, but I'm going to carry it if it delivers when I get there. 7 ounces either way is insignificant or we wouldn't measure it in ounces.

I've not found roof prism designs are worth the extra cost. I'm not saying they don't deliver, I'm saying just not better for looking vs. similar quality porros that will cost far less money because they don't need expensive coatings and materials to deliver the same amount of light at the same quality.

And the porro design engineering is at least a century old - it takes conscious effort to make a short eye relief, narrow FOV 7x50 porro, so even the cheapest discount brand 7x50 offers comfortable eye relief and wide fields with acceptable sharpness across much of the field of view. You can't say the same about $20 roof prism models.

I crossed roof prism designs off the list when I was looking for binoculars because the price-performance ratio was simply broken, IMHO. YMMV, of course.

I'm a birder as well as stargazer, and that is where even the 2x or 3x more you have to pay for a top quality roof starts to make sense. In addition to compact form, the roof's internal focusing, genuine sealing despite center focusing, finely adjustable eyecups, and ED glass objectives (a noticeable improvement in daylight, especially considering the roof binocular's unfortunate greater tendency towards lateral color fringing) are very nice luxury features.

These advantages look even better compared to massively constructed marine Porros with eyepiece focusing--try following and staying focused on warblers 30 feet away with one of those. I "did" it myself for years, but never again.

My favorite binoculars for astronomy are one each:15x60 Docter Nobilem Porro (sharp, bright, and ungainly)10x56 Zeiss FL roof (big, but works great on birds for me)

I agree that if I spent untold hours chasing down birds under a wide variety of weather conditions, I'd probably be using a roof prism binocular.

I live in Nevada, though, and it's usually quite dry; my two little Nikon EII Porros provide all I need under most conditions here. I have one 42mm roof prism bino for general "hard duty" use in poor weather or for travel.

Getting back to the thread title, roof prism binos are certainly suitable for astro use. My Miyauchi Saturn 100mm binoculars are entirely made for astro use and they definitely use a roof prism design...

As Rydberg stated, it costs more to make roof prism designs equal to porro prism performance.

All other things being equal, this is true.

If you want to see this "in action" so to speak, hang out in the binocular section over at BirdForum. for example, every time there is a new 8x32 roof offering from the Teutonic Trinity, one of the first questions is, how do they compare (optically)to the Nikon 8x32 SE (a porro costing 1/4 to 1/5 as much) .

The all weather nature of the roofs is a big plus, if that is a factor for you, for instance you want one bino for travel to do double duty, it will probably be a 42mm-50mm roof.

The 42mm plus roof models from the top end of Nikon and from the Teutonic Trinity, make for excellent night glasses. My cross-over travel bino is an old alpha roof (10x42 Leica BA).

I can only add that I too have mostly written-off roofs simply because of what is and isn't important to me in a binocular. I don't go out to observe in the rain, even when I am looking for birds. So being waterproof is nice but non-essential to me.

I owned a very good Vortex Viper 8.5x50 roof for a number of months and I honestly could not hand-hold it steady. I tried a few different techniques including one that improved things quite a bit, but all my similar sized porros are still better. I believe it is because most of the weight of the roof was in the objectives, while the porros divide much of their weight between the prisms and the objectives thus making them better balanced and easier to hold steady. I would likely have done better with a smaller objective roof, but for astronomy you generally like to go with the bigger objectives whenever possible, and that's where many roofs seem to begin to lose their advantages.

Also, while we often discuss the typical lighter weight of the smaller roofs, it has been pointed out many times that a well made porro can be just as lightweight as a roof, and now that I own a lightweight 10x42 porro that point has come home. Similar roofs will likely still be more "compact" but the real advantage of this in a 8 to 10x42 still eludes me.

Finally, I like wide fields, and most roofs don't offer much along that line. Though the more expensive models seem to do better. We can argue all day about the distortions that follow the wide field images, but it's not so much that I want to stare at something off-axis as it is I just want to see a wide field. If the on-axis image is well corrected, I can deal just fine with most off-axis distortion. Even in astronomy use.

But yes, in the final analysis much of it is about the investment. If roofs were cheaper than porros, I'm sure I'd be looking for reasons to use them. But until that happens, I have little reason to invest the money. When I decide that I really want a binocular that fits in my shirt pocket, I may go looking again. But until then... not likely.